His thoughts are that the power is flowing through the signal circuit, and since so little is being used in the lights now that it’s not being grounded out, and is therefore flowing back through the rest of the circuit. Makes sense to me, and seems to make sense to you too, but I have no idea what a diode is, or how I’d find out more.
Can you install them inline on a wire? Are there frequencies or voltages or anything I’d have to account for? The only thing I know is that the resistors are 3 Ohms each (1 per side).
And dteam, thanks, but I don’t think the bulb is my problem this time. I did a ton of research before I ordered these and I’m pretty sure these are the right bulbs.